Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is characterized by non-cardiogenic pulmonary oedema and respiratoy failure. In 1994, ARDS was defined by the American ? European Consensus Conference (AECC) and since then issues regarding the reliability and validity of this definition have emerged. The Berlin definition was developed by a panel of experts in a convention in 2011 with an initiative of European Society of Intensive Care Medicine endorsed by American Thoracic Society, mainly focussing on feasibility, reliability and validity and objective evaluation of performance. The definition proposed three exclusive categories of ARDS based on degree of hypoxaemia, namely, mild, moderate and severe. The updated and revised Berlin definition of ARDS may serve as model to create a more accurate, evidence based critical illness syndrome and to improve clinical care, research, health services planning and resource management. The article describes clinical, aetiological and physiological basis of ARDS and summarizes how its molecular pathogenesis leads to physiologic alterations of respiratory failure. It provides a physiologic basis for understanding and implementing modern strategies for the respiratory management of patients with ARDS.